The purpose of the proposed project is to provide the candidate with additional career development training in the areas of spoken language development, speech sound disorders in children, and acoustic analysis, to enable the candidate to establish a productive research program geared towards the long-term goals of 1) advancing knowledge of typical development of spoken language production in terms of the various processing stages involved, 2) gaining a more detailed understanding of speech sound disorders in children that may result from disruptions at these processing stages, and 3) bridging the gap between basic science and clinical application. To achieve this purpose, the project includes both career development activities and a research plan designed to gain insight into the representations and real time processes involved in speech sound production in typically developing children as well as in children with speech sound disorders of unknown origin. Several experiments combine chronometric paradigms with speech acoustic analyses to address the emergence of speech planning units (e.g., phonemes) and their deployment in the speech planning process, as well as a number of factors that have been postulated to influence the emergence of these units (e.g., vocabulary size, speech motor skill). The proposed studies focus on children in the age range of 5 to 10 years old, because relatively little is known about speech development in this age range, despite the fact that development of speech production is not complete at age 5 and may affect literacy development. A major long-term goal of this research program is to increase our understanding of speech sound disorders of unknown origin, in particular with respect to the different planning stages affected in different types of disorders such as phonological disorders and childhood apraxia of speech. A combined chronometric-acoustic approach may enable a further delineation and differentiation among children with speech sound disorders, with implications for clinical service delivery for these children in terms of both diagnosis and treatment. PUBLIC HEALTH RELEVANCE: Children with speech sound disorders of unknown origin comprise a large part of the clinical caseload for speech-language pathologists. A complete understanding of the nature of these disorders is lacking, complicating differential diagnosis and treatment. This research will enhance our understanding of typical and atypical development of speech planning and production, with implications for diagnosis and treatment.